1. Field of Invention
The present invention relates to a displaceable working apparatus provided with a platform having an extensible boom and being displaced on a guide rail, and more particularly to a mine working apparatus which is displaced in a mine cavity along a guide rail from an initial position, such as a storage place, to a desired working position along the guide rail, where a working element secured to a working free end of the extensible boom can be displaced into a working area.
2. Description of Prior Art
Many rail mounted working apparatuses have been proposed for displacing working element, such as a platform or a tool, into a working area. Such apparatuses are, for example, described in Moore U.S. Pat. No. 2,846,081, Cox U.S. Pat. No. 4,098,371, Granskog U.S. Pat. Nos. 5,007,863 and 4,960,175, and finally CA 1,183,556 and FR 2,478,190 to Svensson. Moore teaches a boom loader for overhead crane having a horizontally extending rail disposed over a carriage suspended therefrom, a circle track below the carriage and trolley trucks mounted on the tracks for rotational movement in a horizontal plane of a boom secured to the trolley trucks. Cox teaches a mobile scaffold having a carriage for traversing longitudinally a pair of horizontally extending rails disposed in a vertical spaced parallel relationship, which carriage is provided with a pivot assembly rotating in a horizontal plane on which is mounted a parallel arm type boom swinging in a vertical plane pivoting and having an operators platform secured to a free end thereto. In U.S. Pat. No. 4,960,175, Granskog proposes a mine working assembly for raise mining including a drive support displaceable along a guide rail and carrying a drill boom rig and an operators and service platform. A similar type of equipment is taught by Svensson in CA 1,183,556. In U.S. Pat. No. 5,007,683, Granskog further proposes a mine working equipment having a lift cage suspended from a transport guide rail and supporting a drill boom. In FR 2,478,190, Svensson further teaches a rail mounted raise drilling equipement comprising an operators platform and a hoisting device displacing a drill boom. Such prior art apparatuses do not provide full movement of the working element within the working area as required in many applications, such as in mine working. In U.S. Pat. No. 5,113,969 issued to the applicant, a displaceable working platform provided with an extensible boom is described, which boom is secured to a rotating support base mounted on a displaceable platform provided on a main frame, which has stabilizing extension posts secured thereto fir immovably securing the main frame to surrounding surfaces. Such working platform can support a mine worker or a mine working tool over long distances in mine shafts, drifts or along excavated veins disposed transversely to mine galleys. However, while such displaceable working platform is an improvement over other prior art apparatuses, it cannot be used in a mine cavity not capable of supporting a floor standing platform, such as in a deep mining chamber. Furthermore, although the working element provided on such a platform can be easily and quickly retracted from the excavating tunnel without having to displace the main support frame each time the working element is retracted and repositioned, the main support frame still has to be initially displaced from an initial position, such as a storage place, to a desired working position in proximity of the working area.
Therefore, there is still a need to provide a working apparatus that can be easily and quickly installed in a working position and which provides full movement of a working element in a working area.